#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
using namespace std;

class A
{
public:
	A(const int x = 0)
		:_x(x)
	{
		cout << _x << "  ";
		cout << "A(const int x = 0)" << endl;
	}
	A(const A& a)
		:_x(a._x)
	{
		cout << _x << "  ";
		cout << "A(const A& a)" << endl;
	}
	~A()
	{
		_x = 0;
		cout << _x << "  ";
		cout << "~A()" << endl;
	}
private:
	int _x;
};
int main()
{
	A aa1;
	A aa2(10);
	A aa3(aa2);
	return 0;
}
